TIM Brazil has deployed a coherent 100G WDM network over G.653 optical fiber using equipment from Huawei.
The G.653 optical fiber (also called dispersion shifted fiber) used on TIM’s current networks was generally thought to be incompatible with 100G long-haul WDM due to strong non-linear effects such as four-wave mixing (FWM).
Huawei said it was able to overcome these long-haul constraints using modulation format technologies, non-linearity suppression algorithms, and PMD compensation algorithms. Consequently, 100G signals over 1,000km spans have been maintained.
TIM Brazil is a subsidiary of Telecom Italia.
http://www.huawei.com/en/about-huawei/newsroom/press-release/hw-203746-100g.htm
